Apparatus for preparing specimens for chromatographic analysis



6, 1966 G. K. A. BROWNRIGG 3,266,554

APPARATUS FOR PREPARING SPECIMENS FOR CHROMATOGRAPHIC ANALYSIS FiledNov. 29, 1963 5 Sheets-Sheet 1 IN VEN TOR.

GERALDKABMWNR/GG A7- TORNEYJ 6, 1966 G. K. A. BROWNRIGG 3,266,554

APPARATUS FOR PREPARING SPECIMENS FOR CHROMATOGRAPHIC ANALYSIS FiledNov. 29, 1965 5 Sheets-Sheet 2 INVENTOR.

A-rron. N: Y6

5 Sheets-Sheet 3 Aug. 16, 1966 G. K. A. BROWNRIGG APPARATUS FORPREPARING SPECIMENS FOR CHROMATOGRAPHIC ANALYSIS Filed Nov. 29, 1963 16,19 a. K- A- BROWNRIGG 3,266,554

APPARATUS FOR PREPARING SPECIMENS FOR CHROMATOGRAPHIC ANALYSIS FiledNOV. 29, 1963 5 Sheets-Sheet 4 q \S) k\ 1477'ORNE Y5 1966 e. K. A.BROWNRIGG 3,266,554

APPARATUS FOR PREPARING SPECIMENS FOR CHROMATOGRAPHIG ANALYSIS 5Sheets-Sheet 5 Filed Nov. 29, 1963 M Rm 0 Tw mm V00 K P m a 5 A 7-7-oe/vE Y6 United States Patent 3,266,554 APPARATUS FOR PREPARINGSPECIMENS FOR CHROMATOGRAPHIC ANALYSIS Gerald K. A. Brownrigg, GoldenValley, Minn., assignor to Possis Machine Corporation, Minneapolis,Minn., a corporation of Minnesota Filed Nov. 29, 1963, Ser. No. 326,7431 Claims. (Cl. 159-5) The present invention relates to analyticalequipment and more particularly to an apparatus for depositing a liquidsolution to be tested upon an absorptive medium to be used in conductingchromatographic analysis of the materials either dissolved or suspendedin the liquid.

A number of devices have been previously proposed for preparingchromatographic test samples by depositing drops of a fluid at aselected point on a sheet of filter paper. These prior devices have,however, been unsatisfactory in various respects and to some extentineifective in operation.

One important shortcoming of the prior devices of the type describedresults from the fact that an undesirable quantity of dust is frequentlyfound to acco-mulate on the surface of the filter paper at the pointwhere liquid is applied thereto. In many cases this deposit of dust isclearly visible to the naked eye and tends to intenfere with the resultsobtained in the chromatographic test subsequently performed on thepaper.

A further shortcoming of some or the prior devices of the type describedis that there is no reliable means for securely retaining the filterpaper in a selected position upon the apparatus. Occasionally the filterpaper will be disturbed by an operator causing a portion of the fluidwhich is being tested to be applied in one area on the filter paperwhile the remainder of the fluid is applied at a different location. Thetest results in such an event would be valueless.

A still further shortcoming of some of the prior devices of the typedescribed is that the evaporation of liquid from the material depositedon the filter paper often requires a substantial length of time andthere is no means provided for speeding .up the process. The preparationof test specimens therefore requires excessive time.

Another shortcoming of many of the prior devices of the type describedis that the syringe emptying mechanism is positioned immediately abovethe filter paper which is to receive the liquid from the syringes and asa result the nozzles through which the liquid is deposited cannot beeasily lifted away from the filter paper for the convenient removal ofold sheets and the insertion of new sheets. A further shortcoming ofmany of the prior devices of the type described is that the diameter ofthe test sample applied to the filter paper cannot be accurately andreliably controlled.

In view of these and other defects of the prior art it is a generalobject of the present invention to provide an improved apparatus forpreparing samples for chromatographic analysis, which is reliable inoperation, low in cost and rugged in construction.

Another object of the present invention is the provision of an improvedliquid depositing and evaporating apparatus of the type describedwherein the filter paper upon which the test specimen is deposited isreliably held in a selected position.

Another object of the present invention is the provision of an improvedapparatus of the type described in which no dust will collect in thearea that liquid is being deposited upon the filter paper.

Yet another object of the present invention is the provision of animproved apparatus of the type described having means for enabling theevaporation rate to be control-led by regulation of the temperature ofthe air which is circulated for evaporating liquids.

Still another object of the present invention is the provision of animproved apparatus of the type described including an accurate andreliable means for controlling the diameter of the sample deposited onthe filter paper.

Yet another object of the present invention is the provision of animproved apparatus of the type described in which the sheets of filterpaper can be easily placed in position and the liquid depositing nozzlesquickly removed from their operating position when the filter papers areto be removed from the apparatus.

Other objects of the invention will become apparent as the descriptionproceeds.

To the accomplishment of the foregoing and related ends, this inventionthen comprises. the features hereinafter iiully described andparticularly pointed out in the claims, the following descriptionsetting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but a few of the variousways in which the principles of the invention may be employed.

The invention is illustrated by the accompanying drawings in which thesame numerals refer to corresponding parts and in which:

FIGURE 1 is a front elevational view of an apparatus embodying thepresent invention partially broken away;

FIGURE 2 is a plan view of the apparatus of FIG- URE 1;

FIGURE 3 is a side elevational view of the apparatus partially brokenaway;

FIGURE 4 is a transverse vertical sectional view taken on line 4-4 ofFIGURE 2;

FIGURE 5 is a horizontal sectional view taken on line 5-5 of FIGURE 3;

FIGURE 6 is a partial vertical sectional view taken on line 6-6 ofFIGURE 2;

FIGURE 7 is an enlarged partial vertical sectional view taken on line7-7 of FIGURE 2; and

FIGURE 8 is a vertical sectional view taken on line 8-8 of FIGURE 2.

Referring now to the drawings there is shown in FIG- URE 1, a fluiddepositing and evaporating apparatus of the present invention. Theapparatus indicated generally at 10 includes a rectangular support orhousing 12 having a front wall 14, a rear wall 16, top wall 17, sidewalls 18 and 20 and a bottom wall 21. Each corner of the bottom wall 21has secured thereto a downwardly projected leg 22.

Referring to FIGURE 5, rigidly afiixed within the housing 12 upon thebottom wall 21 is a drive means indicated generally at 28 and includinga slow speed drive motor 30 operatively secured to a speed reducingmeans or transmission 31 which is coupled to an output shaft 33. Thetransmission 31 preferably includes a clutch (not shown) which willengage only when the motor 30 is operated.

The drive means 28 also includes a high speed drive motor 32 having anoutput sheave 34. A belt 36 trained about sheave 34 and a sheave 38affixed to the shaft 33 drivably couples motor 32 to the shaft 33. Alsosecured to the shaft 33 is a worm 42 positioned in engagement with aworm wheel 46.

As shown in FIGURE 1, the worm wheel is horizontally positioned abovethe bottom wall 21. Attached to the bottom wall 21 is an upwardlyextending generally U-shaped support bracket 48 upon which is mounted abearing plate 50. Rigidly mounted upon the bearing plate 50 is a journal52 having a ball bearing 54 recessed in its upper end. The lower portionof the worm wheel 46 is fitted in the inner race of the bearing 54. Theupper end of the worm wheel is fitted in a bearing 56 which is itselfmounted within a bearing support collar 58 the latter being mounted upona horizontally disposed plate 60. The worm wheel 46 is provided with avertically extending threaded bore through the center thereof at 62within which is threaded a vertically disposed drive member 64.

The upward end of the drive member 64 projects through the wall 17 ofthe housing 12 as best seen in FIGURE 6. Mounted rigidly at the back ofthe housing 12 and extending vertically therefrom is a support plate 66.Secured to plate 66 is a vertically positioned bracket plate 68 whichencloses the member 64.

Rigidly mounted upon the drive member 64 is a cam 70 including a camlobe 72 positioned when raised to contact a limit switch 73 connected tothe motor 32 by means of conductors 75. The limit switch 73 is normallyclosed and will be opened when contacted by the lobe 72 thereby turningoff the motor 32. Wired to the motor 31 by means of conductors 77 is anormally closed limit switch 79 which is positioned to be contacted bythe cam lobe 72 when the operating member 64 is moved to the lowerdotted line position of FIGURE 6 thereby turning 011 the motor 30.

Rigidly mounted upon the upward end of drive member 64 is a plate 74within which is threadedly mounted a plurality of laterally spaced andvertically disposed adjustment screws 76, each adapted to contact theupward end of a syringe plunger shaft 92 as shown in FIGURE 3.

Upon the bracket plate 68 are mounted a plurality of yieldably retainingclips or brackets 81 in vertically aligned pairs. As shown in FIGURE 7,below each pair of retaining clips 81 is mounted a bracket 78 includinga horizontal slot 80 within which is mounted a coupling 82 preferablyformed from an organic material such as a plastic resin. The couplings82 are each provided with a central vertically disposed bore 84 withinwhich is mounted a tubular extension 86 of a cylindrical container shownas a graduated syringe 88. The container may be viewed as a reservoirfor storing liquid.

Within each of the syringes 88. is mounted for vertical sliding movementa plunger 90 including a vertically disposed plunger shaft 92 as shownin FIGURES 1 and 3. The upward end of each shaft 92 is provided with ahead 4 which during operation engages the lower end of one of theadjustment screws 76.

Communicating with each of the bores 84 in the coupling 82 is a flexibleconduit such as a small plastic tube 98. Each of the tubes 98 extends toand communicates with an elongated nozzle support housing or closureindicated generally at 108 as shown in FIGURE 4. The housing 108 isformed from a generally U-shaped channel 102 having upper and lowerwalls 184 and 106 connected by means of a back wall 108. The front wallof the housing is composed of a transparent member such as a glass plate110 and the housing is closed at each end by means of suitable end walls112.

The upper wall 104 of the housing 102 is provided with a plurality ofspaced apart threaded bores 114 Within which is threaded at each end aremovable plug member 116. (FIGURES 2, 4 and 8.) Between the plugmembers 116 are mounted a plurality of nozzle support assembliesindicated generally at 118.

Each assembly 118, as best seen in FIGURE 4, is composed of a basemember 12f} provided with screw threads at its lower end which projectinto the threaded bores 114. The center of each of the base members 120is bored at 122 and at 126 to receive an elongated cylindrical couplingmember 124 for sliding movement therein along a vertical axis. Thecoupling member 124 is also provided with a shoulder 128. Between theshoulder 128 and a portion of the bore 122 is provided a resilient meanssuch as a spring 138 for yieldably biasing the coupling 124 in an upwarddirection. The base member 120 is provided with a vertical keyway 132into which projects a key 134 adapted to prevent relative rotationbetween the coupling 124 and the base 128. At the center of coupling 124is a bore 136 through which the tube 98 projects. Extending over theupward end of the coupling 124 is an adjustment nut 138 threaded at 1411upon the upward portion of the base 120. As will readily be seen, byturning the adjustment nut 138 in one direction, the coupling 124 andtube 98 can be forced downwardly against the spring 130. When the nut138 is turned in the opposite direction, the spring will force theconnector 124 and the tube 98 upwardly.

Mounted frictionally over the lower end of the connecting member 124 isa neck 142 having a central bore 144 through which the lower portion ofthe tube 98 extends. The lower end of the tube 98 projects a slight distance from the open lower end of the neck 142 to define a nozzle whichis positioned during operation a short distance upwardly of an absorbingmedium such as a piece of filter paper 150.

The nozzle support housing 108 is also provided with a plurality ofbored openings 152 in its lower wall 106 concentric with the lower endof the necks 142. Adjacent the outside of each opening 152 is a circularrecess and a shoulder 154 within which is mounted a rubber sealing ring156. In the top wall 17 in vertical alignment with each of the rings 156has a bore 158. Rigidly secured in alignment with each bore 158 upon thelower surface of wall 17 is a vacuum connector 160 to which is suitablycoupled a vacuum hose 162. As shown in FIGURES 3 and 5, each of thevacuum hoses 162 extends downwardly and is suitably connected to amanifold 164 which is itself rigidly mounted on the bottom wall 21 ofthe housing 12. A vacuum line 166 is secured to the manifold 164 incommunication with each of the lines 162. The other end of the line 166communicates through a T coupling 168 with a vacuum means composed 'of avacuum pump 170 connected through a coupling 171 with an electric drivemotor 174. To this end, a hose 176 is connected between the inlet of thepump 170 and T coupling 168. Also connected to the T coupling 168 is anair pressure control means such as a needle valve 178 which communicatesthrough a vent opening 180 with the atmosphere. The valve 178 includesan adjustment means composed of a needle 182 afiixed to a control knob184. With the pump 170 in operation, by turning the knob 184 in a firstdirection the needle 182 can be withdrawn thereby allowing a greateramount of air to flow through the inlet opening 180 so as to raise thepressure within line 166. By turning the knob 184 in the oppositedirection the amount of air passing into the line 166 through the ventopening 180 can be reduced thereby lowering the pressure within line 166and within each of the lines 162.

Referring to FIG. 2, suitably mounted upon the top of the housing 12 atthe rear thereof are a pair of vertically extending brackets 150 and 152to which are pivotally secured the rearward ends of a generally U-shapedyok'e 155 upon which housing 101) is rigidly mounted. The yoke 155includes a central leg 157 and a pair of parallel side legs 158. Securedto the ends of the housing 100 is a portion 168 of a releasable lockingmeans such as a clasp 162 the lower end of which is rigidly secured tothe side wall of the housing 12.

Thus, during operation, when the filter paper 158 is to be placed in theapparatus for collecting a fluid sample from the syringes, the nozzlesupport yoke 155 is raised thereby elevating the housing 100 andallowing the filter papers 150 to be placed in the desired positionssubstantially as shown in FIGURE 2.

Referring to FIGURE 8, beneath each of the plugs 116 is provided a bore172 and concentric therewith is a sealing ring 173 which projectsdownwardly and is adapted to contact a small section of an air filterpaper which is provided to clean the air used for evaporating liquidfrom spots formed on each of the filter papers 150. Beneath each ring173, the top wall 17 is provided with a bored air inlet opening 177.

The operation of the apparatus will now be described.

To begin the operation the clasps 162 are released and the support arm154 is raised about the pivots 150 and 152 until the housing 100 islifted somewhat above the surface of the top plate 17. At this time, thesheets of filter paper 150 and 175 are placed in position substantiallyas shown in FIGURE 2. The'yoke 154 is then lowered and locked inposition by means of the clasps 162. The syringes 88 are then filled andthe high speed motor 32 is actuated to raise the drive member 64 to thesolid line position of FIGURE 6. The plunger of each of the syringes isthen inserted and the screws 76 are adjusted so that the plungers arelocated in exactly the same position in each syringe. The vacuum motor174 is then started as is the slow speed drive motor 30 which duringoperation causes the drive member 64 to be lowered at a relatively slowrate. As the syringe plungers are slowly lowered, fluid will be expelledthrough the open ends of tubes 98 in the form of relatively small dropswhich after having reached a size sufficient to contact the filterpapers 150 will be quickly absorbed thereby.

Assuming, for example, that the open ends of the tubes 98 are raised byadjustment of the nuts 138 to a relatively great distance above thefilter papers 170, as for example one-quarter inch, the largest dropwhich can fall free from the end of the filter paper is from about 7 to8 mioroliters in volume and will produce a spot of a fairly largediameter on the filter paper. Most operators prefer to form relativelysmall spots. Smaller spots can be produced by lowering the open end oftube 98 through appropriate adjustment of the nut 138 until the dropbeing formed at the end of the tube is picked up before it will fallfree. In practice, it has been found that a drop can be picked up whichis only 2 microliters in volume. The size of the spot formed on thefilter paper can be in this manner substantially reduced.

As the motor 30 operates, the motor 174 driving the pump 170 is alsooperated thereby reducing the pressure on the lower surface of eachfilter paper 150. The air drawn in through this portion of the filterpaper will pass into the housing 102 through the air cleaning filterpapers 175 as can be clearly seen in FIGURE 8. The three motors 174, 30and 32 will cause the housing to become somewhat warmer than the ambientair and thus comprise a heating means which will function to warm theair drawn in through the bore 172 and air cleaning filters 175. In thisway, the evaporation operation can be significantly accelerated.Furthermore, due to the action of the filters 175, there will be noopportunity for dust to accumulate where-fluid is deposited upon each ofthe filter papers 150. If it is desired to reduce the temperature of theair entering housing 100, it is only necessary to remove the plugs 116and place a piece of gauze over the opening 114 in which event not asmuch warm air will enter from the housing 12.

Since the housing 100 and nozzles 118 can be raised simultaneously bythe yoke 155, the filter papers 170 can be quickly and easily replacedwithout disturbing the drive member 64 and the syringe supportingbracket plate 68.

The pressure control knob 184 should be properly adjusted so that thevacuum within the lines 162 is sulficient to draw air through thehousing 101) and filter paper 150 but is not strong enough to damage thefilter paper or in any way hamper the formation of the spots thereon.

It should. be noted that the operation can be observed through the glasswindow 110. It has been found important to observe the operation in thismanner since the volume of the drops can be judged by the time intervalbetween which drops fall onto the filter paper. Thus, a drop which fallsevery 22 seconds will have a volume of approximately 2 microliters whilea drop that falls every 33 seconds will have a volume of approximately 3microliters.

It is apparent that many modifications and variations of this inventionas hereinbefore set forth may be made without departing from the spiritand scope thereof. The specific embodiments described are given by wayof example only and the invention is limited only by the terms of theappended claims.

I claim:

1. An apparatus for depositing fluid on .a coherent sheet-likeabsorptive medium comprising a syringe including a plunger, a support,bracket means mounted upon said support to hold said syringe, a drivemeans including a drive motor, a drive member positioned for slidingmovement upon said support, a drive assembly operatively connectedbetween the drive member and the drive motor, means on the drive memberadapted to engage said plunger, a nozzle, duct means communicatingbetween the syringe and said nozzle, an air-tight housing surroundingsaid nozzle, said housing including an opening positioned concentricwith said nozzle and in vertical alignment therewith on the lower sideof said housing, sealing means mounted around the lower aspect of eachof said opening, support means positioned beneath the sealing means andadapted to receive said sheet-like absorptive medium between the supportmeans and the sealing means, said support means including an opening inalignment with said opening in the housing and vacuum meanscommunicating with the opening in the support means :for providing anair pressure differential across the absonptive medium.

2. The apparatusaccording to claim 1 wherein a nozzle positioning meansis operatively connected between the housing and the nozzle, saidpositioning means including a threaded base member connected to thehousing, an elongated coupling secured to the nozzle and slidablymounted relative to the base member, a resilient member mounted betweenthe coupling and the base member for yieldably biasing the coupling andnozzle in .a first direction and a member operatively abutting againstthe coupling and threadedly connected to the base member for sliding thecoupling and nozzle through the base memher.

3. A liquid depositing and evaporating apparatus for depositing liquidupon a coherent sheet-like absorptive medium comprising in combination ahousing, a drive motor mounted within said housing, a liquid dischargeassembly operatively connected to the drive motor, said assemblyincluding a liquid storage reservoir, a nozzle means communicating withthe reservoir, an enclosure surrounding said nozzle means, saidenclosure having an opening therein in its under face and saidabsorptive medium being adapted to be placed in sealing engagement withsaid opening, an air suction means for creating an air pressuredifferential across the absorptive medium moving the air in theenclosure through the absorptive medium, and port means communicatingwith the enclosure and the interior of the housing whereby the airwithin the housing is drawn by the suction means into the enclosure andthrough the absorptive medium to facilitate evaporation of the liquiddeposited by the nozzle onto the absorptive medium.

4. An apparatus tfOI depositing liquid from a plurality of syringes upona coherent sheet-like absorptive medium and for evaporating the liquidtherefrom comprising in combination a base support, first and seconddrive means mounted on the base support, said first drive means beingadapted to run at a relatively low speed and said second drive meansadopted to run at a relatively high speed, a vertically disposed thirddrive means operatively connected to each of the first and the seconddrive means for vertical movement, a horizontally disposed plungerengaging member mounted at the upward end of the vertically disposedthird drive means, a plurality of syringes having plungers slidablydisposed therein, bracket means on the base support for supporting theplurality of said syringes, adjustable means upon the member forengaging a part of each plunger to vary the extent of movement of theplunger into the syringe, flexible ducts respectively communicating atone end with each syringe, a nozzle at the other end of each of theducts, a common nozzle support housing connected to each of the nozzles,a yoke movably mounted on the base support and supporting the nozzlesupport housing for raising and lowering the nozzles, means forselectively changing the spacing between each nozzle and the basesupport, said nozzle support housing including openings in the lowerwall thereof in alignment with each of the nozzles, a sealing meanspositioned around the openings, said absorptive medium being positionedbetween each sealing means and the top of the base support, port meansin the top of the base support below each of the nozzzles, duct meanscommunicating with each said port means, a source of vacuumcommunicating with said duct means and a pressure adjustment meanscommunicating with said source of vacuum for regulating the pressurethereof and an air filtering means connected with the nozzle supporthousing for removing dust from the air before passing through saidabsorptive medium.

5. The apparatus according to claim 4 wherein the first and second drivemeans include motors connected to a worm, a worm wheel drivably coupledwith said worm and positioned for rotation about a vertical axis, saidworm wheel having a threaded opening therein and the lower end of saidthird drive means being threaded within said threaded opening wherebythe rotation of the worm and resultant rotation of the worm wheel willimpart vertical movement to the vertically disposed drive member.

6. A liquid depositing and evaporating apparatus for depositing liquidon a coherent sheet-like absorbing medium comprising a housing having atop wall formed with an outlet opening, said coherent sheet-likeabsorbing medium positioned on said top wall covering said opening, acontainer for storing liquid, said container having an open top end anda bottom portion having a discharge opening, means supporting thecontainer on the housing, conduit means coupled to said bottom portionfor receiving liquid flowing through the discharge opening, nozzle meanscoupled to said conduit means for receiving liquid carried by theconduit means, enclosure means having a bottom opening positioned onsaid top wall over the outlet opening enclosing said nozzle means and anupper portion of the absorbing medium, said top wall having an air inletopening open to said enclosure means, air filtering means covering saidair inlet opening, support means on said enclosure means for holding thenozzle means in spaced relation relative to the absorbing medium, meansfor forcing liquid from the container into the conduit means fordischarge through said nozzle means onto said absorbing medium, suctionmeans for establishing a vacuum pressure, conduit means connecting thesuction means below said top wall adjacent and surrounding said outletopening whereby air in the enclosure means is drawn through saidabsorbing medium and outlet open ing to facilitate evaporation of liquiddeposited by the nozzle means on the absorbing medium.

7. The apparatus of claim 6 wherein said nozzle means comprises thedischarge end of the conduit means.

8. The apparatus of claim 6 wherein said nozzle support means includesadjustable means for changing the position of the nozzle means relativeto the top wall whereby the nozzle means is selectively adjustabletoward and away from the absorbing medium.

9. The apparatus of claim 6 wherein said means for forcing liquid fromthe container includes a plunger means slidably positioned in thecontainer and drive means for moving the plunger means into thecontainer.

10. The apparatus of claim 6 including a yoke member rigidly connectedto said closure means and pivotally connected to said housing, said yokemember movable upwardly from the top wall and carrying the nozzle meansaway from the absorbing medium.

11. An apparatus for depositing liquid onto a coherent sheet-likeabsorbing medium comprising a housing having a support for the coherentsheet-like absorbing medium, said support having an outlet opening, saidcoherent sheet-like absorbing medium positioned on said support coveringsaid outlet opening, a container for storing liquid, said containerhaving an open end and a portion having a discharge opening, meansattaching said container to a portion of said housing, conduit meanscoupled to said container portion for receiving liquid flowing throughthe discharge opening, nozzle means coupled to said conduit means forreceiving liquid from the conduit means, support means for holding thenozzle means in spaced relationship relative to the top of saidabsorbing medium on the support therefor, plunger means movable into thecontainer through the open top end for forcing liquid from saidcontainer into said conduit means for discharge through said nozzlemeans onto said absorbing medium, said nozzle support means includinghousing means having an air inlet opening and an air outlet opening,said housing means positioned over the support with the air outletopening covered with the sheet-like absorbing medium positioned on saidsupport, and air suction means connected to said outlet opening on thesupport below said absorbing medium for drawing air into said housingmeans through said air inlet opening and out of said housing meansthrough said absorbing medium and outlet opening on the support tofacilitate evaporation of liquid deposited by the nozzle means on thecoherent sheet-like absorbing medium.

12. The apparatus of claim 11 including means for adjusting the positionof the nozzle support means relative to the housing support whereby thenozzle means is adjustable toward and away from the absorbing medium.

13. The apparatus of claim 11 including drive means for moving theplunger means into the container.

14. The apparatus of claim 11 including a yoke member rigidly connectedto said nozzle support means, and pivotally secured to said housing,said member movable relative to said housing to move the nozzle meansaway from the absorbing medium.

15. The apparatus of claim 11 including air filtering means coveringsaid inlet opening of the housing means whereby the air drawn into saidhousing means by the air suction means passes through said air filteringmeans.

16. A liquid dispensing apparatus comprising an elongated containerstationary for storing liquid, said container having an upper open endand a portion including a discharge opening, plunger means slidablypositioned in said container and projected upwardly through said openend, a plate transversely positioned over said plunger means inoperative engagement therewith, a drive member secured to the platemeans, power transmitting means connected to the drive member for movingthe drive member and plate selectively in opposite vertical directionslongitudinally of the container, motor means drivably coupled to saidpower transmitting means for operating the power transmitting meanswhereby the drive member moves in a first direction carrying the platemeans into engagement with the plunger means and moving said plungermeans into the container thereby forcing liquid through said dischargeopening.

17. The apparatus of claim 16 including control means for said motormeans responsive to the position of said drive member for operating themotor means.

18. The apparatus of claim 16 including adjustable means connecting theplate with the plunger means to vary the extent of movement of theplunger means into the container.

19. The apparatus of claim 16 including a support having bracket meansfor releasably holding said container whereby the container can beseparated from the support.

(References on following page) 9 10 References Cited by the Examiner3,013,591 12/1961 Stanley et a1 141-284 X N TED TAT PATENTS 3,113,10312/1963 LOWCI'Y 210198 U I S Es 3,192,990 7/1965 Natelson 1595 9/1918Rogers 141-284 X g; g iii-12g 5 NORMAN YUDKOFF, Primary Examiner. or amGotham Examzner. 12/1960 Hoyer 141-284 X J. SOFER, Assistant Examiner.

5/1961 Magnuson et a1. 210-198

1. AN APPARATUS FOR DEPOSITING FLUID ON A COHERENT SHEET-LIKE ABSORPTIVEMEDIUM COMPRISING A SYRINGE INCLUDING A PLUNGER, A SUPPORT, BRACKETMEANS MOUNTED UPON SAID SUPPORT TO HOLD SAID SYRINGE, A DRIVE MEANSINCLUDING A DRIVE MOTOR, A DRIVE MEMBER POSITIONED FOR SLIDING MOVEMENTUPON SAID SUPPORT, A DRIVE ASSEMBLY OPERATIVELY CONNECTED BETWEEN THEDRIVE MEMBER AND THE DRIVE MOTOR, MEANS ON THE DRIVE MEMBER ADAPTED TOENGAGE SAID PLUNGER, A NOZZLE, DUCT MEANS COMMUNICATING BETWEEN THESYRINGE AND SAID NOZZLE, AND AIR-TIGHT HOUSING SURROUNDING SAID NOZZLE,SAID HOUSING INCLUDING AN OPENING POSITIONED CONCENTRIC WITH SAID NOZZLEAND IN VERTICAL ALIGNMENT THEREWITH ON THE LOWER SIDE OF SAID HOUSING,SEALING MEANS MOUNTED AROUND THE LOWER ASPECT OF EACH OF SAID OPENING,SUPPORT MEANS POSITIONED BENEATH THE SEALING MEANS AND ADAPTED TORECEIVE SAID SHEET-LIKE ABSORPTIVE MEDIUM BETWEEN THE SUPPORT MEANS ANDTHE SEALING MEANS, SAID SUPPORT MEANS INCLUDING AN OPENING IN ALIGNMENTWITH SAID OPENING IN THE HOUSING AND VACUUM MEANS COMMUNICATING WITH THEOPENING IN THE SUPPORT MEANS FOR PROVIDING AN AIR PRESSURE DIFFERENTIALACROSS THE ABSORPTIVE MEDIUM.